Most of the time a squib will not function the slide and cause a jam. The tendency is to clear the jam and keep shooting and that is where you can get hurt or dead. Last week I had a round the did not eject but partially functioned the slide. I had to drop the mag, lock the slide open and check the barrel. You might notice the difference in the recoil. If the round does not eject there is a good chance it did not clear the barrel. By not eject I mean it is still in the chamber. Squibs are extremely dangerous in revolvers where the tendency is to pull the trigger again. There is no jam or malfunction to warn you. Only the recoil and report.
danf_fl; When the police were still using revolvers a range officer/instructor I knew used to make the officers fire their carry load before they could shoot practice rounds. Unbelievable how many squibs, hang fires and failures to fire there were. One of the reasons police went to shooting duty rounds to qualify.

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Patron Member NRA
"I would not be an old man if I had not been an armed young man." JTJ
I was taught to respect my elders but they are getting harder to find.

Yeah, never actually seen one before. Seems a very unlikely thing worth modern factory loads.

I had two out of the same box of Federal. Both happened during a match while shooting my Glock 34. I immediately took some pics and sent them to Federal. They were nice enough to send me a new box free of charge.

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Owner/Armorer at Argyle Armoring, LLC - FFL 07
NRA Life MemberWhat do I know? I'm only a professional.

Yes, it certainly can be caused by a defective primer or one that has been compromised for example someone using WD-40 on their weapons since it is a penetrating oil. Not a good gun lubricant.
But in other cases it can be caused by a short powder drop charge or in some instances no powder at all and the primer ignition drives the bullet into the barrel of the pistol.
The main thing is pay attention to your pistols and if something seems, feels or sounds different "Stop Shooting" until you check it out! Squibs can happen!

03

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The Constitution is not an instrument for the Government to restrain the people. It is an instrument for the people to restrain the Government!
*Patrick Henry

Today, we need a nation of Minutemen, citizens who are not only prepared to take arms, but citizens who regard the preservation of freedom as the basic purpose of their daily life and who are willing to consciously work and sacrifice for that freedom."

I was loading with my progressive yesterday. I loaded about 150 rounds. I noticed a load that looked low. I thought maybe it was my imagination. So I slowly watched as I did the next 5 or 6. They all looked good. Then I kept watching after a couple more good ones I spotted one that had almost no powder. I don't take chances. I used my bullet puller and dissasembled every round that I made.

I had a squib round when I was working up a .32 acp load for an old Iver Johnson revolver that shoots .32 S&W Long. I was expecting it though. I was making it as light as possible to avoid blowing up the gun. After about 5 or 6 trys I made good ammo for it.

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Romans 1:16 I am not ashamed of the gospel, because it is the power of God for the salvation of everyone who believes: first for the Jew, then for the Gentile.

Yeah, never actually seen one before. Seems a very unlikely thing worth modern factory loads.

happens in all ammo. mistakes happen or in the case of remington ammo its the standard...

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"Gun control: The theory that a woman found dead in an alley, raped and strangled with her panty hose, is somehow morally superior to a woman explaining to police how her attacker got that fatal bullet wound." — L. Neil Smith

The problem with being stupid is you cannot simply decide to stop doing dumb things...